888 Solution

Specifications

Command-line CRUD application demonstrating the following functionalities:

Creating sports, events or selections.
Searching for sports, events or selections.
The system should be able to combine N filters with an AND expression.
Filters may be more or less complex.
Updating sports, events or selections.
A sport may have multiple events.
An event may have multiple selections.
When all the selections of a particular event are inactive, the event becomes inactive.
When all the events of a sport are inactive, the sport becomes inactive.
Sports, events and selections need to be persistently stored (SQLite is allowed).

Usage

Usage: [OPTIONS] COMMAND [ARGS]...

Options:
  --install-completion  Install completion for the current shell.
  --show-completion     Show completion for the current shell, to copy it or
                        customize the installation.

  --help                Show this message and exit.

Commands:
  create-event
  create-selection
  create-sport
  search
  update-event
  update-selection
  update-sport

Usage (Docker)

Build

docker compose build

Docker Usage

docker compose run app [ARGS]

# Example:
docker compose run app create-sport Testing Test

Development

ER Diagram

ORM Specification

Since I can't use ORM packages I decided to build my own ORM like app.

ORM API Usage

sports = SportModel().select('Name', 'Slug', 'Active').filter('Name', Operators.Equals, 'name').filter('Active', Operators.Equals, 1).execute()

Filter Operators

=
!=
>
<

Technical Details

Data Validation

Data is validated throughout the application using Pydantic. If invalid data is supplied an exception is thrown. Typer also validates the CLI input.

SOLID Design Principles

SOLID design principles are adhered too throughtout the application. BaseModel is tightly coupled too Mysql but this can be abstracted out through the use of interfaces. ISchema is an example of this. If Pydantic was removed for whatever reason it would not affect the application but we would need to implement the required logic, i.e.:

class ISchema(ABC):

    @abstractmethod
    def get_id(self) -> Optional[int]:
        ...

    @abstractmethod
    def set_id(self, id: int) -> None:
        ...

    @classmethod
    @abstractmethod
    def schema_json(cls) -> str:
        ...

    @classmethod
    @abstractmethod
    def construct(cls, **values: Any) -> Any:
        ...

    @classmethod
    @abstractmethod
    def dict(cls) -> Dict[str, Any]:
        ...

Increased readability and maintainbilty with Typing

The application is typed throughout and validated using Mypy.

$ mypy app
Success: no issues found in 5 source files

Extensible

The application is extensible. A new operator can be added easily by appending it to Operators (enum). For example, a regex filter/operator (REGEXP) could be easily added and the CLI, and filter method would implement it automatically.

Automated Table Creation

If the required Model table doesn't exist then it is automatically created.

Tests

pytest tests
================================================================================================================================================================== test session starts ==================================================================================================================================================================
platform win32 -- Python 3.8.0, pytest-5.4.3, py-1.10.0, pluggy-0.13.1
rootdir: C:\888-solution
plugins: mock-3.6.1
collected 20 items

tests\test_cli.py .......                                                                                                                                                                                                                                                                                                                          [ 35%]
tests\test_models.py ...........                                                                                                                                                                                                                                                                                                                   [ 90%]
tests\test_schemas.py ..                                                                                                                                                                                                                                                                                                                           [100%]

================================================================================================================================================================== 20 passed in 3.17s ===================================================================================================================================================================

Docker Persistant Storage Test

>docker compose build && docker compose run app create-sport Testing Test
[+] Running 1/0
 - Container 888-solution_mysql_db_1  Running                                                                                                                         0.0s
Inserted Sport with ID: 1 successfully.

>docker compose run app create-sport Testing Test
[+] Running 1/0
 - Container 888-solution_mysql_db_1  Running                                                                                                                         0.0s
Inserted Sport with ID: 2 successfully.

>docker compose run app search sport
[+] Running 1/0
 - Container 888-solution_mysql_db_1  Running                                                                                                                         0.0s
Field to filter via: ID
Operator(=, !=, >, <) to filter via: =
Value to filter via: 1
Would you like to add another filter [y/N]: n
Found: [SportSchema(ID=1, Name='Testing', Slug='Test', Active=1)] successfully.

ShaneNolan / 888-solution